The present invention relates to a self-closing valve for the dispensing of flowable media from a container.
There are a number of liquid and fluidized products which are sold to consumers in such containers.
These fluids include, for example, cleansing and personal care products for the human body such as liquid soaps, shower gels, shampoos, skin oils, etc. Another group of such products are foods and condiments such as ketchup, mustard, honey and the like. A third group of these products are utilitarian fluids such as, for example, oils used for technical purposes, etc.
What all these cited products have in common is that the consumer dispenses them from their containers in relatively small quantities.
Conventional containers have a closure cap screwed onto the container neck for this purpose. To dispense the liquid, the container is tilted and the liquid discharged. Depending on the viscosity of the liquid and its intended use, there are a number of different designs, for example small end openings in flexible containers which are squeezed inward to dispense the liquid.
There are numerous proposals within the patent literature for configuring such a container closure having a self-closing valve. This type of valve has the advantage that the user doesn""t have to remove the closure cap each time liquid is to be dispensed.
Yet the demands placed on a self-closing closure are very high. The closure must operate simply because otherwise there would be no advantage over conventional screw closures, and on the other hand it has to exhibit an adequate seal for its respective intended use.
A container closure having a self-closing valve is proposed in EPA 0 545 678 in which a curved membrane is employed which is connected to a retaining lip by means of a connecting wall. The connecting wall is arranged between the membrane and the retaining lip such that it extends in a rolling motion to open the membrane, exerting an opening force on said membrane and inducing it to open.
Starting from this prior art, the present invention puts forth the task of providing a self-closing valve with good opening and sealing qualities which is of small dimensions, which can be inserted into a simply-designed closure cap, and which is easy and economical to produce.
This task is inventively solved by the object of claim 1.
Further embodiments of the present invention comprise the subject matter of the subclaims.
The inventive solution provides for a self-closing valve which, on one hand, opens reliably when pressure is applied to the container in the dispensing position and yet which, on the other hand, closes in a reliable and sealed fashion.
The valve according to the present invention comprises an annular connecting wall which is arranged substantially perpendicular to the longitudinal axis of the container closure or, in other words, which is substantially parallel to the plane in which the closure membrane extends. The membrane is hereby acceded moveability by means of a hinge-like design between the dividing wall and the membrane side wall, yielding what comes close to a flexibly slack suspension of the membrane, and thus preventing the transferring of torque from the dividing wall to the membrane and vice-versa.
The present invention provides for a curved membrane, its curve being directed toward the container interior in the closed position. When the container is squeezed while inverted, meaning when the valve is underneath, an excess pressure is created in the container and the membrane bulges outwardly, whereby slits in the membranes then open, allowing the passage of the fluid.
The membrane and the slits are mated to one another such that upon the membrane""s outward deformation, elastic resilient forces build up in the membrane which, upon depressurization, induce the valve to close.
The membrane and the connecting wall are preferably designed to be rotationally symmetric. In such an embodiment, the support segment is likewise preferably configured to be rotationally symmetric.
The membrane is preferably configured such that it has an approximate semi-spherical shape in the static position. However, the term xe2x80x9csemi-sphericalxe2x80x9d is meant here solely as an indication of the general fundamental design and is not to be considered as an exact geometric definition of the membrane""s form.
The membrane is provided with slits so that it can open.
Particularly in the case of a rotationally symmetric membrane, four or five slits can be provided which in each case extend outwardly from the axis of rotation; i.e. toward the connecting wall.
According to a preferred embodiment of the present invention, one slit is provided which will then extend radially across the axis of rotation.
It is however especially preferred for the membrane to be provided with three slits. In a rotationally symmetric design to the membrane, these slits are arranged such that they extend radially outwardly from the axis of rotation. The slits are preferably disposed at the same angular distance from one another, which amounts to an angle of 120xc2x0.
The use of three slits has particular advantages.
A slitted design having three, four or five slits divides the membrane into a corresponding number of pointed flaps. After deformation and opening, these flaps must be returned to their original position again so that their sectional edges will precisely position against one another. A slight offsetting of the flaps will lead to said flaps, particularly in the area of their tips, riding up over one another, preventing said flaps from having a fully sealed contact.
This kind of problem cannot arise in the case of just one centric alit since the type of flaps as described above are not formed.
The particularly preferred structuring having three slits is based on the knowledge that such flaps, when provided at angles of 120xc2x0, offer far greater protection against lateral displacements and offsettings than flaps provided at just 90xc2x0 or less.
In accordance with another, especially preferred embodiment of the present invention which is as suited for one, but also preferably for three, four, five or more slits, a slit design incorporates at least one material bridge within said slit.
Said material bridge(s) functions like an elastic draw spring within the elastic membrane, pulling the slits back together upon reclosing.
As will be explained in more detail subsequently, such a design provides for a closure which has a strong closing force despite having a low opening force and which induces a reliable guiding of the closure flaps so that their respective side faces will position against one another.
The connecting wall may be configured as a thicker wall, resulting in a very stable supporting of the membrane relative a closure cap. It is, however, also possible to configure the connecting wall in a thinner fashion.
In the case of a thick-walled and thus rigid connecting wall, it is particularly preferred that the membrane and the connecting wall are decoupled as regards torque; i.e. that membrane movement is affected as little as possible by the forces and especially by the torque which could be transmitted from the connecting wall to the membrane.
This condition is yielded by a hinge-like connection between the connecting wall and the membrane. Such a hinge can be produced in various different ways. Especially preferred is a thin segment arranged in the area of connection between the connecting wall and the membrane and which rotates about the membrane when same is of rotationally symmetric design. In order to enhance the hinge effect, said thin segment is preferably of S-shape in cross-section.
As described above, the contact surface between connecting wall and membrane is preferably configured in such a manner that especially no torque will be transmitted from the connecting wall to the membrane. In accordance with a preferential design, this contact surface can also be realized with the use of inhomogeneous material in this area, meaning, for example, that another material is used in this area or that the properties of the material are appropriately controlled so as to attain the desired diminishing of the ability to transfer torque.
The valve according to the present invention may be manufactured from any material which exhibits the appropriate properties for the elastic deformation and the elastic resilient strength.
It is particularly preferable to manufacture the membrane and/or the connecting wall from a silicone material. It is furthermore possible to manufacture the membrane and/or the connecting wall from a thermoplastic elastomer. When so doing, the connecting wall, the support segment and the membrane are all preferably of the same material and form a valve body.
Especially preferred is the reinforcing of the self-closing valve""s support segment with synthetic means, a plastic ring in the case of a rotationally symmetric design to the valve, which in contrast to the material of the connecting wall and the membrane, is made from a rigid and, where applicable, also more economical synthetic material.
In accordance with a preferred embodiment, a reinforcing ring made of a harder plastic is molded onto the support segment. When so doing, it is preferable that the plastic ring is manufactured in a separate prior manufacturing step from that of the self-closing valve and that a plurality of openings are provided on said reinforcing ring into which the valve material can penetrate during the molding process so that a deep, lasting and moreover reasonably-priced connection is created between the reinforcing ring and the valve body.
It is preferred to use polyamide as the material for the reinforcing ring.
The injection molding process may be especially preferably designed such that the polyamide ring and the silicone membrane are molded directly subsequent one another and in particular in a manner in which the polyamide is first injected into the injecting tool, the injecting tool is then subsequently opened and brought to another cavity arrangement with the silicone then being injected into this other cavity.
When an injection is made simultaneously to a second or, as preferred, to several valves, the polyamide material for the producing of the ring is then in turn injected into a number of second cavities.
Thus a first sequence phase ensues in which only polyamide rings are injected and then the polyamide rings are respectively molded in a phase of simultaneous injection of silicone to said previously-molded polyamide rings so as to then result in one, respectively the total number of valves being molded in one respective sequence phase.
It must be noted that such an approach is not limited to polyamide and silicone materials but rather can also be realized with other materials, thermoplastic elastomers, etc.
The terms xe2x80x9cfluid,xe2x80x9d xe2x80x9cliquidsxe2x80x9d and xe2x80x9cmediumxe2x80x9d or xe2x80x9cflowable mediumxe2x80x9d as used in the present description are to be understood as all substances having a viscosity which allows for their being discharged from a container, if necessary by means of an additional exertion of pressure, regardless of whether said viscosity is dynamic or kinematic. Hence these terms include not only such substances which flow on their own such as, for example, watery substances, but also substances which may only flow when pressure is applied to them such as, for example, greasy or pasty substances.
In accordance with a first preferential use, the closure is used for food products and those food products of the group comprising the following foods: vegetable and fruit juices and other drinks, seasoning sauces of all types such as soy sauce and the like, viscous seasonings such as mustard, ketchup, mayonnaise and viscous foods such as honey, jellies, jams, and milk products like milk, condensed milk, cream, etc.
It is furthermore preferred to employ the valve in the packaging of personal care and cleansing products such as liquid or pasty soap, shower gels, skin oils, sun tanning or blocking preparations, shampoos, hair colorants, skin creams, deodorants, etc.
Use of the valve is additionally preferred with other cleaning and care products such as dishwashing liquids, universal cleaning agents, shoe creams, polishes, stain removers, liquid detergents and the like.
Use of the closure is also preferred for pharmaceutical products and preferably for products which are consumed in small quantities such as, for example, eye drops, nose drops, disinfectants, and all types of pharmaceutical products regardless of whether they are for internal or external usage.
A further preferential use is that with technical products such as, for example, paints, varnishes, solvents, lubricants and other technical chemical and substance mixtures.